/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.wst.jsdt.internal.ui.javaeditor;



import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.IWidgetTokenKeeper;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.IVerticalRuler;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StackLayout;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.ui.IActionBars;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IFileEditorInput;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.ActionContext;
import org.eclipse.ui.actions.ActionGroup;
import org.eclipse.ui.texteditor.IDocumentProvider;
import org.eclipse.ui.texteditor.ITextEditorActionConstants;
import org.eclipse.ui.texteditor.IWorkbenchActionDefinitionIds;
import org.eclipse.wst.jsdt.core.IClassFile;
import org.eclipse.wst.jsdt.core.IJavaScriptElement;
import org.eclipse.wst.jsdt.core.IJavaScriptModelStatusConstants;
import org.eclipse.wst.jsdt.core.IJavaScriptProject;
import org.eclipse.wst.jsdt.core.JavaScriptModelException;
import org.eclipse.wst.jsdt.core.dom.JavaScriptUnit;
import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
import org.eclipse.wst.jsdt.internal.ui.JavaUIStatus;
import org.eclipse.wst.jsdt.internal.ui.actions.CompositeActionGroup;
import org.eclipse.wst.jsdt.internal.ui.util.ExceptionHandler;
import org.eclipse.wst.jsdt.internal.ui.util.PixelConverter;
import org.eclipse.wst.jsdt.ui.actions.RefactorActionGroup;

/**
 * Java specific text editor.
 */
public class ClassFileEditor extends JavaEditor implements ClassFileDocumentProvider.InputChangeListener {


	/**
	 * A form to attach source to a class file.
	 */
	private class SourceAttachmentForm implements IPropertyChangeListener {

		private Composite fComposite;
		private Color fBackgroundColor;
		private Color fForegroundColor;
		private Color fSeparatorColor;
		private List fBannerLabels= new ArrayList();
		private List fHeaderLabels= new ArrayList();
		private Font fFont;

		/**
		 * Creates a source attachment form for a class file.
		 * 
		 * @param file the class file
		 */
		public SourceAttachmentForm(IClassFile file) {
		}

		/**
		 * Creates the control of the source attachment form.
		 * 
		 * @param parent the parent composite 
		 * @return the creates source attachment form
		 */
		public Control createControl(Composite parent) {

			Display display= parent.getDisplay();
			fBackgroundColor= display.getSystemColor(SWT.COLOR_LIST_BACKGROUND);
			fForegroundColor= display.getSystemColor(SWT.COLOR_LIST_FOREGROUND);
			fSeparatorColor= new Color(display, 152, 170, 203);

			JFaceResources.getFontRegistry().addListener(this);

			fComposite= createComposite(parent);
			fComposite.setLayout(new GridLayout());
			fComposite.addDisposeListener(new DisposeListener() {
				public void widgetDisposed(DisposeEvent e) {
					JFaceResources.getFontRegistry().removeListener(SourceAttachmentForm.this);
					fComposite= null;
					fSeparatorColor.dispose();
					fSeparatorColor= null;
					fBannerLabels.clear();
					fHeaderLabels.clear();
					if (fFont != null) {
						fFont.dispose();
						fFont= null;
					}
				}
			});

			createTitleLabel(fComposite, JavaEditorMessages.SourceAttachmentForm_title);
			createLabel(fComposite, null);
			createLabel(fComposite, null);

			createHeadingLabel(fComposite, JavaEditorMessages.SourceAttachmentForm_heading);

			Composite separator= createCompositeSeparator(fComposite);
			GridData data= new GridData(GridData.FILL_HORIZONTAL);
			data.heightHint= 2;
			separator.setLayoutData(data);

//			try {
//				IPackageFragmentRoot root= getPackageFragmentRoot(fFile);
//				if (root != null) {
//					createSourceAttachmentControls(fComposite, root);
//				}
//			} catch (JavaScriptModelException e) {
//				String title= JavaEditorMessages.SourceAttachmentForm_error_title;
//				String message= JavaEditorMessages.SourceAttachmentForm_error_message;
//				ExceptionHandler.handle(e, fComposite.getShell(), title, message);
//			}

			separator= createCompositeSeparator(fComposite);
			data= new GridData(GridData.FILL_HORIZONTAL);
			data.heightHint= 2;
			separator.setLayoutData(data);

			fNoSourceTextWidget= createCodeView(fComposite);
			data= new GridData(GridData.FILL_BOTH);
			fNoSourceTextWidget.setLayoutData(data);
			
//			updateCodeView(fNoSourceTextWidget, fFile);
			
			return fComposite;
		}

//		private void createSourceAttachmentControls(Composite composite, IPackageFragmentRoot root) throws JavaScriptModelException {
//			IIncludePathEntry entry;
//			try {
//				entry= root.getRawIncludepathEntry();
//			} catch (JavaScriptModelException ex) {
//				if (ex.isDoesNotExist())
//					entry= null;
//				else
//					throw ex;
//			}
//			IPath containerPath= null;
//
//			if (entry == null || root.getKind() != IPackageFragmentRoot.K_BINARY) {
//				createLabel(composite, Messages.format(JavaEditorMessages.SourceAttachmentForm_message_noSource, fFile.getDisplayName()));
//				return;
//			}
//
//			IJavaScriptProject jproject= root.getJavaScriptProject();
//			if (entry.getEntryKind() == IIncludePathEntry.CPE_CONTAINER) {
//				containerPath= entry.getPath();
//				JsGlobalScopeContainerInitializer initializer= JavaScriptCore.getJsGlobalScopeContainerInitializer(containerPath.segment(0));
//				IJsGlobalScopeContainer container= JavaScriptCore.getJsGlobalScopeContainer(containerPath, jproject);
//				if (initializer == null || container == null) {
//					createLabel(composite, Messages.format(JavaEditorMessages.ClassFileEditor_SourceAttachmentForm_cannotconfigure, containerPath.toString())); 
//					return;
//				}
//				String containerName= container.getDescription();
//				IStatus status= initializer.getSourceAttachmentStatus(containerPath, jproject);
//				if (status.getCode() == JsGlobalScopeContainerInitializer.ATTRIBUTE_NOT_SUPPORTED) {
//					createLabel(composite, Messages.format(JavaEditorMessages.ClassFileEditor_SourceAttachmentForm_notsupported, containerName));  
//					return;
//				}
//				if (status.getCode() == JsGlobalScopeContainerInitializer.ATTRIBUTE_READ_ONLY) {
//					createLabel(composite, Messages.format(JavaEditorMessages.ClassFileEditor_SourceAttachmentForm_readonly, containerName));  
//					return;
//				}
//				entry= JavaModelUtil.findEntryInContainer(container, root.getPath());
//				Assert.isNotNull(entry);
//			}
//
//
//			Button button;
//
//			IPath path= entry.getSourceAttachmentPath();
//			if (path == null || path.isEmpty()) {
//				createLabel(composite, Messages.format(JavaEditorMessages.SourceAttachmentForm_message_noSourceAttachment, root.getElementName()));
//				createLabel(composite, JavaEditorMessages.SourceAttachmentForm_message_pressButtonToAttach);
//				createLabel(composite, null);
//
//				button= createButton(composite, JavaEditorMessages.SourceAttachmentForm_button_attachSource);
//
//			} else {
//				createLabel(composite, Messages.format(JavaEditorMessages.SourceAttachmentForm_message_noSourceInAttachment, fFile.getDisplayName()));
//				createLabel(composite, JavaEditorMessages.SourceAttachmentForm_message_pressButtonToChange);
//				createLabel(composite, null);
//
//				button= createButton(composite, JavaEditorMessages.SourceAttachmentForm_button_changeAttachedSource);
//			}
//
//			button.addSelectionListener(getButtonListener(entry, containerPath, jproject));
//		}
//
//		private SelectionListener getButtonListener(final IIncludePathEntry entry, final IPath containerPath, final IJavaScriptProject jproject) {
//			return new SelectionListener() {
//				public void widgetSelected(SelectionEvent event) {
//					Shell shell= getSite().getShell();
//					try {
//						IIncludePathEntry result= BuildPathDialogAccess.configureSourceAttachment(shell, entry);
//						if (result != null) {
//							applySourceAttachment(shell, result, jproject, containerPath);
//							verifyInput(getEditorInput());
//						}
//					} catch (CoreException e) {
//						String title= JavaEditorMessages.SourceAttachmentForm_error_title;
//						String message= JavaEditorMessages.SourceAttachmentForm_error_message;
//						ExceptionHandler.handle(e, shell, title, message);
//					}
//				}
//
//				public void widgetDefaultSelected(SelectionEvent e) {}
//			};
//		}

		/*
		 * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent)
		 */
		public void propertyChange(PropertyChangeEvent event) {

			for (Iterator iterator = fBannerLabels.iterator(); iterator.hasNext();) {
				Label label = (Label) iterator.next();
				label.setFont(JFaceResources.getBannerFont());
			}

			for (Iterator iterator = fHeaderLabels.iterator(); iterator.hasNext();) {
				Label label = (Label) iterator.next();
				label.setFont(JFaceResources.getHeaderFont());
			}

			fComposite.layout(true);
			fComposite.redraw();
		}

		// --- copied from org.eclipse.update.ui.forms.internal.FormWidgetFactory

		private Composite createComposite(Composite parent) {
			Composite composite = new Composite(parent, SWT.NONE);
			composite.setBackground(fBackgroundColor);
			//		composite.addMouseListener(new MouseAdapter() {
			//			public void mousePressed(MouseEvent e) {
			//				((Control) e.widget).setFocus();
			//			}
			//		});
			return composite;
		}

		private Composite createCompositeSeparator(Composite parent) {
			Composite composite = new Composite(parent, SWT.NONE);
			composite.setBackground(fSeparatorColor);
			return composite;
		}

		private StyledText createCodeView(Composite parent) {
			int styles= SWT.V_SCROLL | SWT.H_SCROLL | SWT.MULTI | SWT.FULL_SELECTION;
			StyledText styledText= new StyledText(parent, styles);
			styledText.setBackground(fBackgroundColor);
			styledText.setForeground(fForegroundColor);
			styledText.setEditable(false);
			return styledText;
		}

		private Label createLabel(Composite parent, String text) {
			Label label= new Label(parent, SWT.WRAP);
			if (text != null) {
				label.setText(text);
			}
			label.setBackground(fBackgroundColor);
			label.setForeground(fForegroundColor);
			GridData gd= new GridData();
			gd.widthHint= new PixelConverter(label).convertWidthInCharsToPixels(80);
			label.setLayoutData(gd);
			return label;
		}

		private Label createTitleLabel(Composite parent, String text) {
			Label label = new Label(parent, SWT.NONE);
			if (text != null) {
				label.setText(text);
			}
			label.setBackground(fBackgroundColor);
			label.setForeground(fForegroundColor);
			label.setFont(JFaceResources.getHeaderFont());
			fHeaderLabels.add(label);
			return label;
		}

		private Label createHeadingLabel(Composite parent, String text) {
			Label label = new Label(parent, SWT.NONE);
			if (text != null) {
				label.setText(text);
			}
			label.setBackground(fBackgroundColor);
			label.setForeground(fForegroundColor);
			label.setFont(JFaceResources.getBannerFont());
			fBannerLabels.add(label);
			return label;
		}

//		private void updateCodeView(StyledText styledText, IClassFile classFile) {
//			String content= null;
//			ClassFileBytesDisassembler disassembler= ToolFactory.createDefaultClassFileBytesDisassembler();
//			try {
//				content= disassembler.disassemble(classFile.getBytes(), "\n", ClassFileBytesDisassembler.DETAILED); //$NON-NLS-1$
//			} catch (JavaScriptModelException ex) {
//				JavaScriptPlugin.log(ex.getStatus());
//			} catch (ClassFormatException ex) {
//				JavaScriptPlugin.log(ex);
//			}
//			styledText.setText(content == null ? "" : content); //$NON-NLS-1$
//		}
	}

	/**
	 *  Updater that takes care of minimizing changes of the editor input.
	 */
	private class InputUpdater implements Runnable {

		/** Has the runnable already been posted? */
		private boolean fPosted= false;
		/** Editor input */
		private IClassFileEditorInput fClassFileEditorInput;


		public InputUpdater() {
		}

		/*
		 * @see Runnable#run()
		 */
		public void run() {

			IClassFileEditorInput input;
			synchronized (this) {
				input= fClassFileEditorInput;
			}

			try {

				if (getSourceViewer() != null) {
					setInput(input);
				}

			} finally {
				synchronized (this) {
					fPosted= false;
				}
			}
		}

		/**
		 * Posts this runnable into the event queue if not already there.
		 *
		 * @param input the input to be set when executed
		 */
		public void post(IClassFileEditorInput input) {

			synchronized(this) {
				if (fPosted) {
					if ((input != null) && input.equals(fClassFileEditorInput)) {
						fClassFileEditorInput= input;
					}
					return;
				}
			}

			if ((input != null) && input.equals(getEditorInput())) {
				ISourceViewer viewer= getSourceViewer();
				if (viewer != null) {
					StyledText textWidget= viewer.getTextWidget();
					if ((textWidget != null) && !textWidget.isDisposed()) {
						synchronized (this) {
							fPosted= true;
							fClassFileEditorInput= input;
						}
						textWidget.getDisplay().asyncExec(this);
					}
				}
			}
		}
	}


	private StackLayout fStackLayout;
	private Composite fParent;

	private Composite fViewerComposite;
	private Control fSourceAttachmentForm;

	private CompositeActionGroup fContextMenuGroup;

	private InputUpdater fInputUpdater= new InputUpdater();
	
	/**
	 * The copy action used when there's attached source.
	 * 
	 */
	private IAction fSourceCopyAction;
	/**
	 * The Select All action used when there's attached source.
	 * 
	 */
	private IAction fSelectAllAction;

	/**
	 * StyledText widget used to show the disassembled code.
	 * if there's no source.
	 * 
	 * 
	 */
	private StyledText fNoSourceTextWidget;

	
	/**
	 * Default constructor.
	 */
	public ClassFileEditor() {
		super();
		setDocumentProvider(JavaScriptPlugin.getDefault().getClassFileDocumentProvider());
		setEditorContextMenuId("#ClassFileEditorContext"); //$NON-NLS-1$
		setRulerContextMenuId("#ReadOnlyJavaScriptRulerContext"); //$NON-NLS-1$
		setOutlinerContextMenuId("#ClassFileOutlinerContext"); //$NON-NLS-1$
		// don't set help contextId, we install our own help context
	}

	/*
	 * @see AbstractTextEditor#createActions()
	 */
	protected void createActions() {
		super.createActions();

		setAction(ITextEditorActionConstants.SAVE, null);
		setAction(ITextEditorActionConstants.REVERT_TO_SAVED, null);

		fSourceCopyAction= getAction(ITextEditorActionConstants.COPY);
		fSelectAllAction= getAction(ITextEditorActionConstants.SELECT_ALL);

		final ActionGroup group= new RefactorActionGroup(this, ITextEditorActionConstants.GROUP_EDIT, true);
		fActionGroups.addGroup(group);
		fContextMenuGroup= new CompositeActionGroup(new ActionGroup[] {group});

		/*
		 * 1GF82PL: ITPJUI:ALL - Need to be able to add bookmark to class file
		 *
		 *  // replace default action with class file specific ones
		 *
		 *	setAction(ITextEditorActionConstants.BOOKMARK, new AddClassFileMarkerAction("AddBookmark.", this, IMarker.BOOKMARK, true)); //$NON-NLS-1$
		 *	setAction(ITextEditorActionConstants.ADD_TASK, new AddClassFileMarkerAction("AddTask.", this, IMarker.TASK, false)); //$NON-NLS-1$
		 *	setAction(ITextEditorActionConstants.RULER_MANAGE_BOOKMARKS, new ClassFileMarkerRulerAction("ManageBookmarks.", getVerticalRuler(), this, IMarker.BOOKMARK, true)); //$NON-NLS-1$
		 *	setAction(ITextEditorActionConstants.RULER_MANAGE_TASKS, new ClassFileMarkerRulerAction("ManageTasks.", getVerticalRuler(), this, IMarker.TASK, true)); //$NON-NLS-1$
		 */
	}

	/*
	 * @see AbstractTextEditor#editorContextMenuAboutToShow(IMenuManager)
	 */
	public void editorContextMenuAboutToShow(IMenuManager menu) {
		super.editorContextMenuAboutToShow(menu);

		ActionContext context= new ActionContext(getSelectionProvider().getSelection());
		fContextMenuGroup.setContext(context);
		fContextMenuGroup.fillContextMenu(menu);
		fContextMenuGroup.setContext(null);
	}

	/*
	 * @see JavaEditor#getElementAt(int)
	 */
	protected IJavaScriptElement getElementAt(int offset) {
		if (getEditorInput() instanceof IClassFileEditorInput) {
			try {
				IClassFileEditorInput input= (IClassFileEditorInput) getEditorInput();
				return input.getClassFile().getElementAt(offset);
			} catch (JavaScriptModelException x) {
			}
		}
		return null;
	}

	/*
	 * @see JavaEditor#getCorrespondingElement(IJavaScriptElement)
	 */
	protected IJavaScriptElement getCorrespondingElement(IJavaScriptElement element) {
		if (getEditorInput() instanceof IClassFileEditorInput) {
			IClassFileEditorInput input= (IClassFileEditorInput) getEditorInput();
			IJavaScriptElement parent= element.getAncestor(IJavaScriptElement.CLASS_FILE);
			if (input.getClassFile().equals(parent)) {
				return element;
			}
		}
		return null;
	}

	/*
	 * 1GEPKT5: ITPJUI:Linux - Source in editor for external classes is editable
	 * Removed methods isSaveOnClosedNeeded and isDirty.
	 * Added method isEditable.
	 */
	/*
	 * @see org.eclipse.ui.texteditor.AbstractTextEditor#isEditable()
	 */
	public boolean isEditable() {
		return false;
	}

	/*
	 * @see org.eclipse.ui.texteditor.AbstractTextEditor#isEditorInputReadOnly()
	 * 
	 */
	public boolean isEditorInputReadOnly() {
		return true;
	}

	/**
	 * Translates the given editor input into an <code>ExternalClassFileEditorInput</code>
	 * if it is a file editor input representing an external class file.
	 *
	 * @param input the editor input to be transformed if necessary
	 * @return the transformed editor input
	 */
	protected IEditorInput transformEditorInput(IEditorInput input) {

		if (input instanceof IFileEditorInput) {
			IFile file= ((IFileEditorInput) input).getFile();
			IClassFileEditorInput classFileInput= new ExternalClassFileEditorInput(file);
			if (classFileInput.getClassFile() != null) {
				input= classFileInput;
			}
		}

		return input;
	}

	/*
	 * @see AbstractTextEditor#doSetInput(IEditorInput)
	 */
	protected void doSetInput(IEditorInput input) throws CoreException {
		uninstallOccurrencesFinder();

		input= transformEditorInput(input);
		if (!(input instanceof IClassFileEditorInput)) {
			throw new CoreException(JavaUIStatus.createError(
					IJavaScriptModelStatusConstants.INVALID_RESOURCE_TYPE,
					JavaEditorMessages.ClassFileEditor_error_invalid_input_message,
					null));
		} 

		JavaScriptModelException e= probeInputForSource(input);
		if (e != null) {
			IClassFileEditorInput classFileEditorInput= (IClassFileEditorInput) input;
			IClassFile file= classFileEditorInput.getClassFile();
			IJavaScriptProject javaProject= file.getJavaScriptProject();
			if (!javaProject.exists() || !javaProject.isOnIncludepath(file)) {
				throw new CoreException(JavaUIStatus.createError(
						IJavaScriptModelStatusConstants.INVALID_RESOURCE,
						JavaEditorMessages.ClassFileEditor_error_classfile_not_on_classpath,
						null)); 
			} else {
				throw e;
			}
		}

		IDocumentProvider documentProvider= getDocumentProvider();
		if (documentProvider instanceof ClassFileDocumentProvider) {
			((ClassFileDocumentProvider) documentProvider).removeInputChangeListener(this);
		}

		super.doSetInput(input);

		documentProvider= getDocumentProvider();
		if (documentProvider instanceof ClassFileDocumentProvider) {
			((ClassFileDocumentProvider) documentProvider).addInputChangeListener(this);
		}

		verifyInput(getEditorInput());
		
		final IJavaScriptElement inputElement= getInputJavaElement();

		Job job= new Job(JavaEditorMessages.OverrideIndicatorManager_intallJob) {
			/*
			 * @see org.eclipse.core.runtime.jobs.Job#run(org.eclipse.core.runtime.IProgressMonitor)
			 * 
			 */
			protected IStatus run(IProgressMonitor monitor) {
				JavaScriptUnit ast= JavaScriptPlugin.getDefault().getASTProvider().getAST(inputElement, ASTProvider.WAIT_YES, null);
				if (fOverrideIndicatorManager != null) {
					fOverrideIndicatorManager.reconciled(ast, true, monitor);
				}
				if (fSemanticManager != null) {
					SemanticHighlightingReconciler reconciler= fSemanticManager.getReconciler();
					if (reconciler != null) {
						reconciler.reconciled(ast, false, monitor);
					}
				}
				if (isMarkingOccurrences()) {
					installOccurrencesFinder(false);
				}
				return Status.OK_STATUS;
			}
		};
		job.setPriority(Job.DECORATE);
		job.setSystem(true);
		job.schedule();
		
	}

	/*
	 * @see IWorkbenchPart#createPartControl(Composite)
	 */
	public void createPartControl(Composite parent) {

		fParent= new Composite(parent, SWT.NONE);
		fStackLayout= new StackLayout();
		fParent.setLayout(fStackLayout);

		fViewerComposite= new Composite(fParent, SWT.NONE);
		fViewerComposite.setLayout(new FillLayout());

		super.createPartControl(fViewerComposite);

		fStackLayout.topControl= fViewerComposite;
		fParent.layout();

		try {
			verifyInput(getEditorInput());
		} catch (CoreException e) {
			String title= JavaEditorMessages.ClassFileEditor_error_title;
			String message= JavaEditorMessages.ClassFileEditor_error_message;
			ExceptionHandler.handle(e, fParent.getShell(), title, message);
		}
	}

	private JavaScriptModelException probeInputForSource(IEditorInput input) {
		if (input == null) {
			return null;
		}

		IClassFileEditorInput classFileEditorInput= (IClassFileEditorInput) input;
		IClassFile file= classFileEditorInput.getClassFile();

		try {
			file.getSourceRange();
		} catch (JavaScriptModelException e) {
			return e;
		}

		return null;
	}

	/**
	 * Checks if the class file input has no source attached. If so, a source attachment form is shown.
	 * 
	 * @param input the editor input 
	 * @throws JavaScriptModelException if an exception occurs while accessing its corresponding resource 
	 */
	private void verifyInput(IEditorInput input) throws JavaScriptModelException {

		if ((fParent == null) || (input == null)) {
			return;
		}

		IClassFileEditorInput classFileEditorInput= (IClassFileEditorInput) input;
		IClassFile file= classFileEditorInput.getClassFile();
		
		IAction copyQualifiedName= getAction(IJavaEditorActionConstants.COPY_QUALIFIED_NAME);
		
		boolean wasUsingSourceCopyAction= fSourceCopyAction == getAction(ITextEditorActionConstants.COPY);

		// show source attachment form if no source found
		if (file.getSourceRange() == null) {

			// dispose old source attachment form
			if (fSourceAttachmentForm != null) {
				fSourceAttachmentForm.dispose();
			}

			SourceAttachmentForm form= new SourceAttachmentForm(file);
			fSourceAttachmentForm= form.createControl(fParent);

			fStackLayout.topControl= fSourceAttachmentForm;
			fParent.layout();

			if (fNoSourceTextWidget != null) {
				// Copy action for the no attached source case
				final IAction copyAction= new Action() {
					public void run() {
						fNoSourceTextWidget.copy();
					}
				};
				copyAction.setActionDefinitionId(IWorkbenchActionDefinitionIds.COPY);
				setAction(ITextEditorActionConstants.COPY, copyAction);
				copyAction.setEnabled(fNoSourceTextWidget.getSelectionText().length() > 0);
				fNoSourceTextWidget.addSelectionListener(new SelectionListener() {
					public void widgetSelected(SelectionEvent e) {
						copyAction.setEnabled(fNoSourceTextWidget.getSelectionText().length() > 0);
					}
					public void widgetDefaultSelected(SelectionEvent e) {
					}
				});
				
				// Select All action for the no attached source case
				final IAction selectAllAction= new Action() {
					public void run() {
						fNoSourceTextWidget.selectAll();
						copyAction.setEnabled(true);
					}
				};
				selectAllAction.setActionDefinitionId(IWorkbenchActionDefinitionIds.SELECT_ALL);
				setAction(ITextEditorActionConstants.SELECT_ALL, selectAllAction);
				copyAction.setEnabled(fNoSourceTextWidget.getSelectionText().length() > 0);
				copyQualifiedName.setEnabled(false);
				
				
			}

		} else { // show source viewer

			if (fSourceAttachmentForm != null) {
				fSourceAttachmentForm.dispose();
				fSourceAttachmentForm= null;

				fStackLayout.topControl= fViewerComposite;
				fParent.layout();
			}

			setAction(ITextEditorActionConstants.COPY, fSourceCopyAction);
			setAction(ITextEditorActionConstants.SELECT_ALL, fSelectAllAction);
			copyQualifiedName.setEnabled(true);

		}
		
		IAction currentCopyAction= getAction(ITextEditorActionConstants.COPY);
		boolean isUsingSourceCopyAction=  fSourceCopyAction == currentCopyAction;
		if (wasUsingSourceCopyAction != isUsingSourceCopyAction) {
			IActionBars actionBars= getEditorSite().getActionBars();
			
			if (isUsingSourceCopyAction) {
				createNavigationActions();
			} else {
				for (int i= 0; i < ACTION_MAP.length; i++) {
					IdMapEntry entry= ACTION_MAP[i];
					actionBars.setGlobalActionHandler(entry.getActionId(), null);
					setAction(entry.getActionId(), null);
				}
			}
			
			actionBars.setGlobalActionHandler(ITextEditorActionConstants.COPY, currentCopyAction);
			actionBars.setGlobalActionHandler(ITextEditorActionConstants.SELECT_ALL, getAction(ITextEditorActionConstants.SELECT_ALL));
			actionBars.updateActionBars();
		}
		
	}

	/*
	 * @see ClassFileDocumentProvider.InputChangeListener#inputChanged(IClassFileEditorInput)
	 */
	public void inputChanged(IClassFileEditorInput input) {
		fInputUpdater.post(input);
	}

	/*
	 * @see JavaEditor#createJavaSourceViewer(Composite, IVerticalRuler, int)
	 */
	protected ISourceViewer createJavaSourceViewer(Composite parent, IVerticalRuler ruler, int styles, IPreferenceStore store) {
		return new JavaSourceViewer(parent, ruler, null, false, styles, store) {

			public boolean requestWidgetToken(IWidgetTokenKeeper requester) {
				if (PlatformUI.getWorkbench().getHelpSystem().isContextHelpDisplayed()) {
					return false;
				}
				return super.requestWidgetToken(requester);
			}

			public boolean requestWidgetToken(IWidgetTokenKeeper requester, int priority) {
				if (PlatformUI.getWorkbench().getHelpSystem().isContextHelpDisplayed()) {
					return false;
				}
				return super.requestWidgetToken(requester, priority);
			}
		};
	}

	/*
	 * @see org.eclipse.ui.IWorkbenchPart#dispose()
	 */
	public void dispose() {
		// http://bugs.eclipse.org/bugs/show_bug.cgi?id=18510
		IDocumentProvider documentProvider= getDocumentProvider();
		if (documentProvider instanceof ClassFileDocumentProvider) {
			((ClassFileDocumentProvider) documentProvider).removeInputChangeListener(this);
		}
		super.dispose();
	}

	/*
	 * @see org.eclipse.ui.IWorkbenchPart#setFocus()
	 */
	public void setFocus() {
		super.setFocus();

		if ((fSourceAttachmentForm != null) && !fSourceAttachmentForm.isDisposed()) {
			fSourceAttachmentForm.setFocus();
		}
	}

}
